After WEEKS of reading both sides of the wall issue; I've come to the following conclusion, as to what the real difference is between those wanting the wall and those who don't.

Those who don't want the wall, would rather focus on the illegal immigrants being caught AFTER they ender the US; no matter how they enter

and

Those who want the wall would rather stop them from entering the US illegally, to begin with.

Side note:
No one has suggested that the wall is going to stop ALL illegal immigration; but once it curtails the ground border problem, the other methods can then be looked at.